In many instances, the refuse trucks encounter different kinds of refuse containers, and it is desirable that these different containers be lifted by the same lifting mechanism on the refuse truck upwardly towards the top of the truck and then inverted to empty the contents. Then, the container is rotated back and carried down to the ground level where the truck lift mechanism is automatically disconnected from the container. Usually, to connect the lifting mechanism on the truck to a container having hooks, the lifting mechanism is brought into alignment and hooked onto the container hooks. Upward traveling heads on the lifting mechanism slide along tracks on opposite sides of the truck body and are raised by the truck operator to an upper emptying position. Then the emptied container is lowered by the heads and then the container is unhooked from the lifting mechanism.
Typically, the single hook containers have T-shaped hooks projecting from the sides of container adjacent the center of the vertical sidewalls of the container. The T-shaped hooks are straight, horizontal bars projecting forwardly of a front sidewall of the container and have an integral cross bar extending transversely across a distal, free end of the horizontal bar. The truck lifting head has a slot to receive the horizontal bar and a plate to be positioned behind the cross bar. Usually, the containers have a sloped, top cover that is pivotally mounted for swinging from a closed position to an open position when the container is inverted by the lifting mechanism. A pair of clamps carried by the head swing into position to clamp the hooks from disengagement with the head as the container is pivoted down to empty its contents and is pivoted up to return to its normal, upright position.
Typically, the double hook container has a pair of upper and lower hooks projecting forwardly from each of the vertical sidewalls of the container beyond the front wall of the container. The hooks have downwardly pointed ends with interior, upwardly-extending slots leading to a vertical wall defining the interior side of the slots. The truck head has a pair of members, such as pins, that are raised and cam into the downwardly-opening, pair of slots. With upper and lower pins inserted into the upper and lower slots of the upper and lower hooks, the heads will travel upwardly along curved tracks to lift the double hook container and then swing and invert the container to empty its contents into the truck's interior chamber. The clamping mechanism on the heads holds the pins in the hooks as the container pivots and the slots face upwardly into the container emptying position. After emptying and lowering the container, the engaged pins on the truck are lowered from the hook slots and the truck moves away from the container to dislodge from the container.
The above-described hooks and containers as well as the conventional heads are only described as being exemplary of the hooks and heads, which may differ from that described and illustrated herein. This invention is not limited to the described or illustrated hooked containers or the heads and left mechanisms, but it is intended to cover various kinds of hooked containers and lifting mechanisms.
It will be appreciated that handling of these large containers, which may have heavy refuse therein, and which are impacted by the truck require relatively strong and rugged parts that are being impacted and subject to heavy loads. Thus, mechanisms or parts that are employed to allow conversion between single hook containers and double hook containers must be sufficiently strong to withstand rough handling conditions and high loads. Moreover, the conversion pieces to equip a conventional lift mechanism capable of handling only one style of container to lift both styles of containers should be low cost. The conversion should be simple so that it can be done by one person, as there may be only one driver on the refuse truck. Also, the conversion should be done relatively quickly so that refuse collection is not greatly delayed by converting back and forth between single and double hook-up containers. Thus, there is a need for a new and improved head lift mechanism for use with either single or double hook containers.